Perhaps you should try some spelling variations:
thanh trung » thanh tung
thieu qua » thieu cua, thieu quang, thien quan
cam nhung » nam nhung, tham nhung, cam nang
cam hung » cac chung, cam nang, van hung
cong dan » cong san, cong tan, huong dan
dan toan » van toan, dan than, manh toan
toan cau » toan cao, toan ban, toan tap

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: hoc ((hieu qua) OR (thieu qua)) - thanh trung ((cam nhung) OR (cam hung)) cong dan toan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc ((hieu qua) or (thieu qua)) - thanh trung ((cam nhung) OR (cam hung)) cong dan toan cau~".
• Adding a wildcard symbol may retrieve word variants: hoc ((hieu qua) or (thieu qua)) - thanh trung ((cam nhung) OR (cam hung)) cong dan toan cau*.